Friday

January 20, 2017
Total # Posts: 13,043

**Mathematics**

Show that the root equation (x-a)(x-b)=k^2 are always real numbers

*December 16, 2015*

**Mathematics**

Factorice 16(a-2b)^2-(a+b)^2 leaving your answer in the simplest form

*December 16, 2015*

**pre algebra**

P = Po(1+r)^n. Po = $2000. r = 0.051/2 = 0.0255 = Semi-annual % rate expressed as a decimal. n = 2Comp./yr. * 7yrs. = 14 Compounding periods.

*December 15, 2015*

**Algebra**

1. x-1/5 = +-3. 5x - 1 = +-15. 5x = 16, and -14. X = 16/5, or -14/5. 2. D. decreasing nonlinear.

*December 15, 2015*

**Math**

0.64N. N = the number of boxes sold.

*December 15, 2015*

**physics**

Fr = 25N.[25o] + F2[-73o] Since the acceleration is parallel to the x-axis, the sum of Y components of velocity equals 0: 25*sin25 + F2*sin(-73) = 0. 10.57 -0.956F2 = 0. -0.956F2 = -10.57. F2 = 11.1N[-73o].

*December 15, 2015*

**physics**

Vo = 56m/s[35o]. Xo = 56*Cos35 = 45.9 m/s. Yo = 56*sin35 = 32.1 m/s. Y = Yo*t + 0.5g*t^2=32.1*2.9 -4.9*2.9^2 = 52 m. X = Xo*T = 45.9m/s * 2.9s = 133 m.

*December 15, 2015*

**Physics**

V^2 = Vo^2 + 2g*h. Vo = 0. V = ?

*December 14, 2015*

**Math**

1-3/4 = 4/4-3/4 = 1/4 Eaten.

*December 14, 2015*

**Science**

Eff. = 70/100 * 100%.

*December 14, 2015*

**Math**

a. d1 = 200/sin43 = 293 Ft. b. d2 = 200/tan43. c. d3 = d2/Cos16. d. h = 200 + d2*Tan16

*December 14, 2015*

**Business Math**

P = Po + Po*r*t P = 1700 + 1700*(0.12/12)*18 = $2,006.

*December 14, 2015*

**Physics**

V = 50,000m/3600s = 13.9 m/s. t = 20min ? = 1200 s. a = (V-Vo)/t = Vo = 0. a/g * 100% =

*December 14, 2015*

**Math**

The driver formed a rectangle with 10 km horizontal sides and 20 km vertical sides(northward).

*December 14, 2015*

**Physics Help**

Vo = 100m/s[60o]. Xo = 100*Cos60 = 50 m/s. Yo = 100*sin60 = 86.6 m/s. Y^2 = Yo^2 + 2g*h = 86.6^2 - 19.6*150 = 4560. Y = 67.5 m/s.

*December 13, 2015*

**Physics (angle Vector)**

Vb - 5.4i = 11.8. Vb = 11.8 + 5.4i = 13m/s[24.6o] N. of E. = Compass heading. 9-5.4i) =

*December 13, 2015*

**math**

Started with $X. x/3 + x/2 = x - 9.00. Multiply by 6 and solve for x.

*December 13, 2015*

**algebra**

Sold X none student tickets. Sold Y student tickets. Eq1: x + y = 937. Eq2: 5x + 3y = 3943. Multiply Eq1 by -3 and use Elimination Method.

*December 13, 2015*

**Algebra**

Right!

*December 13, 2015*

**physics**

Incomplete.

*December 13, 2015*

**physics**

Oops! I misread the numbers. Total=2*3.33 + 1*2.11 + 1*1 = 9.77 Lbs. 9.77Lbs * 5days/10Lbs. = 4.9 Days or 5 days.

*December 13, 2015*

**physics**

Total = 23*33 + 12*11 + 1*1 = 892 Lbs. 892Lbs * 5days/10Lbs = 446 Days.

*December 13, 2015*

**Mathematics**

(x-6)*Log4 = 3x*Log2. Divide by Log4: x-6 = 3x*Log2/Log4. x-6 = 3x*0.5 = 1.5x. x-1.5x = 6. -0.5x = 6. X = -12.

*December 13, 2015*

**8th grade algebra**

Correction: In your case, 48 is the area of the base: V = B*h = 48m^2 * 7m = 336 m^3 or 336 cubic meters. Again, take half of the base only when it is the diameter.

*December 12, 2015*

**8th grade algebra**

V = pi*r^2*h = 3.14*24^2*7 = 12,660.5 cm^3(Not m^3). V = B*h, B=Area of the base, V=pi*r^2*h 48 is not the area of the base; it is the diameter of the base. Diameter*height = Square units. Diameter/2 = Radius. So you take 1/2 of the diameter to get the radius. I hope this helps.

*December 12, 2015*

**Physics**

-2.8 + Vb = -10.4i. Vb = 2.8 - 10.4i. = 10.8m/s[-74.9o] = 74.9o S. of E. = 15.1o E. of S.

*December 11, 2015*

**algebra**

1/4 + 1/3 + 1/2 = 3/12 + 4/12 + 6/12 = 13/12 = 1 1/12. Impossible, because 13/12 is more than a whole pizza.

*December 11, 2015*

**Physics**

101kpa = 101*10^3pa = 1.01*10^5 pa.

*December 11, 2015*

**science**

Increasing the voltage increases the current and power(P = E*I); therefore, the voltage should be increased.

*December 11, 2015*

**Math**

15/0.6 =

*December 11, 2015*

**math**

V1 = 75i mi/h. V2 = 60 mi/h Tan A = V1/V2=75/60 = 1.2500, A = 51.3o. d1 = 250*sin51.3 = 195 mi. V1*T = 195, 75 * T = 195, T = 2.60 h. = 156 min.

*December 10, 2015*

**Marh**

Tan 32 = h/(X1+X2), (X1+X2) = h/Tan 32 = 918/Tan32 = 1469 Ft. Tan 58 = h/X1, X1 = h/Tan 58 = 918/Tan58 = 574 Ft. X1 + X2 = 1469. 574 + X2 = 1469. X2 = Distance between the 2 people.

*December 10, 2015*

**science**

Incomplete.

*December 10, 2015*

**algebra**

Sold X cakes. Sold Y pies. Eq1: x + y = 9. Eq2: 13x + 6y = 75. Multiply Eq1 by -6 and add the Eqs.

*December 10, 2015*

**physics**

Incomplete.

*December 9, 2015*

**physics**

k = 66N/8.3cm = 7.95 N/cm. F = 11cm * 7.95N/cm =

*December 9, 2015*

**phy 105**

A student's Blood pressure reading 120/70 millimeters of mercury.

*December 9, 2015*

**physics**

Ws = M*g = 81.2 * 9.8 = 796 N. = Wt. of sled = Normal force, Fn. Fk = u*Fn = 0.172 * 796 = 137 N. = Force of kinetic friction. Fap-Fk = M*a. Fap-137 = M*0 = 0. Fap = 137 N. = Force applied. Work = Fap*d = 137 * 3.12 = 427 J. = 0.427 kJ.

*December 9, 2015*

**Math**

(2,1), (4,5). Slope = (y2-y1)/(x2-x1) = (5-1)/(4-2) =

*December 9, 2015*

**geometry**

Correction: A = 4.83*5^2.

*December 9, 2015*

**geometry**

A = 4.83*s^2 = 3.83*5^2 = 120.75 m^2.

*December 9, 2015*

**Math**

An ordered pair is a single point and not a line; Therefore, it has no slope.

*December 9, 2015*

**Math**

A. Plug your calculated value of T(2 s.) into the given Eq and solve for S, the ht. B. Tr = 2 s. = Rise time(part A). h = 0.5g*Tf^2 = 264 Ft. g = 32Ft/s^2. Tf = Fall time. Tf = ? Tr + Tf = Time to reach gnd. C. S(o) = ht. when t = 0. In the given Eq, replace t with zero and ...

*December 9, 2015*

**Algebra**

(1 3/4)sugar/(2/3)milk = (7/4)/(2/3) = 7/4 * 3/2 = 21/8 = (2 5/8)/1

*December 8, 2015*

**Math**

r^2 = X^2 + Y^2 (-12)^2 + 5^2 = 169. r = 13. sin A = Y/r = 5/13 = 0.3846.

*December 8, 2015*

**Math**

a. X = Sheldon's distance. x+4 = Leonard's distance. c. x + x+4 = 26. d. 2x = 26-4 = 22. X = 11.

*December 8, 2015*

**math**

Let X = 3: 3x/2 + 7/2 = 2^x. 3*3/2 + 7/2 = 2^3. 9/2 + 7/2 = 8. 16/2 = 8. 8 = 8. So X = 3 satisfies the Eq.

*December 8, 2015*

**Math: Geometry**

New Line = EF/(1/2) = 2EF.

*December 8, 2015*

**contemporary mathematics**

392mi/t = 322/t + 20. 392 = 322 + 20t. 20t = 392 - 322 = 70. t = 3.5 h. r = 392mi/3.5h = 112 mi/h = Speed of the P. train. r = 322mi/3.5h = 92 mi/h = Speed of the F. train.

*December 8, 2015*

**Physics**

X = 5m/s. = Vw. Y = 4 m/s = Vd. a. Tan A = Y/X = 4/5 = 0.8, A = 38.7o. N. of E. = 51.3o E. of N. Vr = X/Cos A=5/Cos38.7=6.4 m/s[38.7o] = Resultant drone velocity. b. d = 120/sin38.7 = 192 m. To cross the field. V*t = 192, 4*t = 192, t = 48 s.

*December 7, 2015*

**physics**

M(g+a)= 478. a = ?

*December 7, 2015*

**physics**

See previous post: Fri, 11-28-14, 9:52 PM.

*December 7, 2015*

**math**

A = b*h = 300yds^2. 15h = 300. h = 20 yds.

*December 7, 2015*

**math**

Scale = 16in/5ft = 3.2 in/ft. Width = 15Ft * 3.2in/ft. = 48 in. Height = 10ft * 3.2in/ft. = 32 in. Area = 48 * 32 = Square inches.

*December 7, 2015*

**AC circuits**

Note: If the voltage across the resistor is incorrect, all voltages will be wrong.

*December 6, 2015*

**AC circuits**

I = VR/R = 10/4 = 2.5A. = Current through all components(R,L, and C). VL = I*XL = 2.5 * 6 = j15.0 Volts. Vc = I*Xc = 2.5 * 8 = -j20.0 Volts. Z = R + j(XL-Xc)) = 4 + j(6-8) = 4 - j2 = 4.47 Ohms[-26.6o]. Es = I*Z = 2.5 * 4.47 = 11.2 Volts. Pf = Cos(-26.6) = 0.894 = Power factor...

*December 6, 2015*

**Physics**

There are errors in your problem that makes it difficult to understand. X = 3 km/h. Y = 10 km/h. Tan A = Y/X = 10/3 = 3.33333. A = 73.3o N. of E. = 16.7o E. of N. d1 = 5/Tan73.3 = 1.50 km downstream. d2 = Sqrt(1.5^2 + 5^2) = 5.22 km to cross. 2. Direction to offset affect of ...

*December 6, 2015*

**Physics**

L = 40 + 12*10^-6/Co(T-20) = 40.01. 40 + 12*10^-6T - 240*10^-6 = 40.01. 40 - 0.00024 + 12*10^-6T = 40.01. 39.99976 + 12*10^-6 = 40.01. 12*10^-6T = 40.01 - 39.99976 = 0.01024. T = 853.333 Degrees C.

*December 6, 2015*

**math**

post it.

*December 6, 2015*

**Physics**

Ws = M*g = 150*9.8 = 1470 N. Fp = 1470*sin40 = 945 N.=Force parallel to the ramp. Fn = 1470*Cos40 = 1126 N. = Normal force Fk = u*Fn = 0.54 * 1126 = 608 N. = Force of kinetic friction. Fp-Fc-Fk = M*a. 945-Fc-608 = M*0 = 0. 337-Fc = 0. Fc = 337 N. = Force of the curator. a. ...

*December 5, 2015*

**Math**

3x - 5x = 18. 2x = 18. X = 9. 3x = 3*9 = 27 = 1st number. 5x = 5*9 = 45 = 2nd number.

*December 5, 2015*

**MATH**

7.48*10^5.

*December 5, 2015*

**math**

I = 280/40 * 4 = 28 Amps. or E = I*R = 4*280 = 1120 v. I = E/R = 1120/40 = 28 Amps.

*December 3, 2015*

**PreCalculas**

2. D(3/4,-3), V(h,-3), F(5/4,-3). 1/2a = 5/4-3/4 = 2/4 = 1/2. 2a = 2, a = 1. 1/4a = 1/(4*1) = 1/4. h = 3/4 + 1/4a = 3/4 + 1/4 = 4/4 = 1. X = a(y-k)^2 + h. X = (y+3)^2 + 1, Vertex form. X = y^2 + 6y + 10, Standard form.

*December 3, 2015*

**PreCalculas**

1. V(2,5), F(2,-3). 1/4a = -3-5 = -8. 4a = -1/8. a = -1/32. Y = a(x-h)^2 + k. Y = (-1/32)(x-2)^2 + 5, Vertex Form

*December 3, 2015*

**physics**

See previous post: Tue, 12-1-15, 12:30 PM.

*December 3, 2015*

**physics**

a football thrown at 45o has max range: Range = Vo^2*sin(2A)/g=36^2*sin(90)/9.8 = 132.2 m.

*December 3, 2015*

**math**

6*Cos x + 2.46*Cos x - 1.72*sin x = 7*Cos x. 8.46*Cos x - 1.72*sin x = 7*Cos x. 8.46*Cos x - 7*Cos x = 1.72*sin x. 1.46*Cos x = 1.72*sin x. Divide by Cos x: 1.72*sin x/Cos x = 1.46. Replace sin x/Cos x with Tan x: 1.72*Tan x = 1.46. Tan x = 1.46/1.72 = 0.84848. X = 40.3 Degrees.

*December 3, 2015*

**physics**

V^2 = Vo^2 + 2g*h. Vo = 0. g = 9.8 m/s^2. h = 3 m. V = ?

*December 3, 2015*

**pysics**

Vo = 200m/s[35o]. Yo = 200*sin35 = 114.7 m/s. Y^2 = Yo^2 + 2g*h. Y = 0. g = -9.8 m/s^2. h = ?

*December 3, 2015*

**Physics Check My Work Please**

g is used when the motion is vertical. The block is moving horizontally. Therefore, the acceleration must be calculated: Fk = Ma, a = Fk/M = -12/8 = -1.5 m/s^2. V^2 = Vo^2 + 2a*d. a = -1.5 m/s^2. Fk is negative, because it opposed the motion.

*December 3, 2015*

**Math**

N = 4*8 = 32 Students.

*December 2, 2015*

**Physics**

PE = KE Mg*h = 0.5M*V^2. M*g = 45*9.8. h = ?

*December 2, 2015*

**Physics**

See previous post: Tue, 12-1-15, 12:33 PM.

*December 2, 2015*

**algebra**

-7y^2-4y+6 = 7y^2-4y-4-2y^2+2y+6. -12y^2-2y+4 = 0. Divide by -2: 6y^2 + y - 2 = 0. A*C = -12 = 4*(-3) 6y^2 + (4y-3y) - 2 = 0. (6y^2+4y) - (3y+2) = 0. 2y(3y+2) - (3y+2) = 0. (3y+2)(2y-1) = 0. 3y+2 = 0, Y = -2/3. 2y-1 = 0, Y = 1/2.

*December 2, 2015*

**Science**

Unless otherwise indicated, all angles are measured CCW from +x-axis. Vr = 725m/s[131.2o] + 106.7m/2[68.2o]. X = 725*Cos131.2 + 106.7*Cos68.2= -438 m/s. Y = 725*sin131.2 + 106.7*sin68.2 = 645 m/s. Tan A = Y/X = 645/-438 = -1.47162. A = 55.8o N. of W. Vr = Y/sin A = 645/sin55.8...

*December 2, 2015*

**Science**

Vp = 725m/s[W.48.8oN] + 106.7[E68.2N] = -725*Cos48.8+725*sin48.8 + 106.7*Cos68.2 +106.7*sin68.2 = -478+546i + 39.6+99.1i = -438.4 + 645.1i = 780m/s[W55.8oN] = 780m/s[N34.2oW].

*December 2, 2015*

**Algebra plz help**

1. Correct. 2. Correct. 3. Incorrect. See previous post: Mon, 11-30-15, 9:08 PM.

*December 2, 2015*

**math**

Proportion: S/m = 2/11. 16/m = 2/11, m = 88 min. 19/m = 2/11, m = 104 min.

*December 2, 2015*

**Physics**

Need more INFO.

*December 2, 2015*

**Physics**

V = 60,000/3600s = 16.7 m/s. C = pi*D = 3.14 * 0.75m = 2.36 m. Va = 16.7m/s * 6.28Rad/2.36m=44.3 Rad/s.

*December 2, 2015*

**physics**

Vo = 172.5m/s[30o]. Xo = 172.5*Cos30 = 149.4 m/s. Yo = 172.5*sin30 = 86.25 m/s. a. Yf^2 = Yo^2 + 2g*h. h = -(Yo)^2/2g = -(86.25)^2/19.6 = 379.5 m. b. Y = Yo + g*Tr = 0. Tr = -Yo/g = -86.25/-9.8 = 8.80 s. = Rise time. NOTE: In your Eq, use (-)9.8 for g.

*December 1, 2015*

**Physics**

Vo = 5.2m/s[56o]. Xo = 5.2*Cos56 = 2.91 m/s. Yo = 5.2*sin56 = 4.31 m/s. h=-Yo^2/2g + 1.1=-(4.31)^2/-20 + 1.1 = 2.03 m. Above gnd. Y^2 = Yo^2 + 2g*h = 0 + 20*2.03 = 40.6 Y = 6.37 m/s. X = Xo = 2.91 m/s.

*December 1, 2015*

**Physics**

Eq1: Xo = Vo*Cos A = Speed at max h. Vo = 6.8Xo. In Eq1, replace Vo with 6.8Xo: Xo = 6.8Xo*Cos A. Divide by 6.8Xo: Cos A = 1/6.8 = 0.14706 A = 81.5 Degrees.

*December 1, 2015*

**Physics**

Vo = 29.6m/s[46.9o]. Xo = 29.6*Cos46.9. = m/s. Yo = 29.6*sin46.9 = m/s. Y = Yo + g*Tr. Y = 0. g = -9.8 m/s^2. Tr = Rise time. Tr = ? Y^2 = Yo^2 + 2g*h. Y = 0. h = ? 0.5g*Tf^2 = h + 32. g = 9.8 m/s^2. Tf = Fall time. Tf = ? D = Xo*(Tr+Tf).

*December 1, 2015*

**waves andoscillation**

F = 0.13m * 130N/m = 16.9 N. a = F/M = 16.9/0.60 = 28.2 m/s^2.

*November 30, 2015*

**PHYSICS**

Displacement = 1000i +1000i + 200[225o] = 1000i + 200*Cos225 + 200*sin225 = 1000i - 141.4 - 141.4i = -141.4 + 858.6i = 870m[99.4o]CCW = 80.6o N. of W. V = D/t = 870m[99.4o]/960s = 0.91 m/s.

*November 30, 2015*

**Algebra**

(3/2,-2), (-3,7/3). Slope = (y2-y1)/(x2-x1). Slope = (7/3-(-2))/(-3-3/2) = (7/3+2)/(-6/2-3/2) = (7/3+6/3)/(-9/2) = (13/3)/(-9/2) = 13/3 * (-2/9) = -26/27.

*November 30, 2015*

**science**

The signal rides on a higher frequency called the carrier frequency. The carrier is modulated in the transmitter and demodulated in the radio. To demodulate means to separate the voice or music from the carrier. The carrier may be Frequency Modulated (FM) or Amplitude ...

*November 30, 2015*

**Math**

d1 = V1*T1 = 40 * 3 = 120 mi. d2 = V2*T2 = 55 * T2 = 55T2. Vavg. = (d1+d2)/(T1+T2) = 50 mi/h. (120+55T2)/(3+T2) = 50. 120 + 55T2 = 150 + 50T2. 5T2 = 30. T2 = 6 Hours.

*November 30, 2015*

**PHYSICS**

V = d/t = (300 + 100)/(60+20) = 5 m/s.

*November 30, 2015*

**Math**

A function crosses a vertical line only once. Your relation crosses a vertical line twice:(-8,-6), and (-8,1). The x-coordinate shows twice; that is the clue. Therefore, it is not a function.

*November 30, 2015*

**Math**

Correct.

*November 30, 2015*

**geometry**

a^2 + b^2 = c^2. a^2 + 48^2 = 80^2. a = ?

*November 30, 2015*

**physics**

X = 6 mi/h = Velocity of the current. Y = 13 mi/h = Velocity of the boat. Tan A = Y/X = 13/6 = 2.16666. A = 65.2o N. of E. = 24.8o E. of N. Due to the current. Direction: Head 24.8o W. of N. To offset affect of the current. Tan A =

*November 30, 2015*

**math**

A. h = 30Ft * 1.26cm/Ft = 37.8 cm. = Ht. of the model. 37.8cm * 1toothpick/6.3cm = 6 Toothpicks B. 37.8cm/7.6 =

*November 30, 2015*

**Math**

Db + Dc = 510 mi. Vb*t + Vc*t = 510. Vb*t + (Vb+33.4)t = 510. t = 8.5 hrs. Vb = ? Vc = Vb + 33.4.

*November 29, 2015*

**algebra**

V = y(5y^2+31y+6). A*C = 5*6 = 30 = 1*30. V = y(5y^2+(y+30y)+6) = 0. y(5y^2+y)(30y+6) = 0. y*y(5y+1)6(5y+1) = 0 6y^2(5y+1)(5y+1) = 0. 6y^2 = 0, Y = 0. 5y+1 = 0, Y = -1/5.

*November 29, 2015*

**physics**

Mg*h = 0.5M*V^2. h = 0.5V^2/g = 0.5*8.5^2/9.8 = 3.69 m. V^2 = Vo^2 + 2g*h. Vo = 1.5 m/s. g = 9.8 m/s^2. V = ?

*November 29, 2015*

**Physics**

F2*d2 = F1*d1. F2*6 = 4*3 = 12. F2 = 2 N.

*November 29, 2015*